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Figure 25: Examples of Hubble Space Telescope observations of BL Lac objects. This sequence shows the isophotes around three BL Lac objects: (left) 0548-322 - with a clearly imaged elliptical host galaxy; (middle) 1534+014 - which is resolved and can be shown to have isophotes that correspond to a normal elliptical galaxy; (right) 0820+255 - in which the host galaxy is unresolved. In all three cases the emission from the point-like AGN has been masked out